Use $PMT=\frac{P(\frac{r}{n})}{[1-(1+\frac{r}{n}{)}^{-nt}]}$ to determine the regular

payment amount, rounded to the nearest dollar. The

price of a small cabin is $$80,000.$ The bank requires

a $5\%$ down payment. The buyer is offered two

mortgage options: $20-$year fixed at $8\mathrm{.}5\%$ or $30-$year fixed

at $8\mathrm{.}5\%.$ Calculate the amount of interest paid for each

option. How much does the buyer save in interest with

the $20-$year option?

Find the monthly payment for the $20-$year option.